Ripper for well casings



Feb. 23 1926.

,I J. A'. FRANCIS RIPPER FOR WELL cAsINGs Filed Nov. s, 1924 INVENTOR XETN www;

m7,! f ATTORNEYS um llas- 'Patented Feb. 23, 1926..

JOHN ARTHUR FRANCIS, 0F PARKERTON, `WYO'IMIIN't'zi'l I.

I RIPPER FOB. 'WELL CASINGS.

Application led November 3, 1924. Serial No. 747,662.

To all whomA t may concern.'

Be it known that I, JOHN ARTHUR FpANoIs, a citizen of the United States, and a resident of Parkerton, county of Converse, and State fof Wyoming, have invented a new and useful Improvement in Rippers for Well Casings, of which the following is a full, clear, and exact description.

My invention relates to improvements in devices for ripping well casings, so as ,to render the removal of the casingcomparatively easy, and it consists in the combinations, constructions, and arrangements herein described and claimed. I

It often happens that the casings of wells, such as oil wells, become fastened in the hole, so that'it cannot be removed from the hole, except by parting it from the place where it is fast.

An object of my invention is to rovide a device which may be inserted wit in the casing and which, by the use of the ordinary well drilling' machinery, such as jars and the like, will cut the joint which is fast, thus permittingthe casing to be removed,

A further object of my invention is to provide a device of the type described, which is Vrelatively 'simple in. construction but positive in action.

Other objects and advantages will appear in the following specification, and the novel features of the invention will be particularly pointed out in the appended claims.

My invention is illustrated in the accompanying drawings, forming part of this application, in which Figure 1 is a side view of the casing ripper, certain parts being shown in section for the sake of clearness,

Figure 2 is a View of the casing ripper in operative position in a well casing, this view being at right angles to Figure 1,

Figure 3 is a fragmentary sectional view showing the position of the cutters in the casing ripper as it enters the casing, and

Fi re 4 is a similar view showing the position of the parts after the cut has been completed.

In carrying out my invention, I rovide a body portion 1, having a tapere screw 2 at the end thereof arranged to be secured to the bottom member of a set of jars of ordinary construction. The body portion 1 has an integral reduced extension 3 which bears at its end a head 4. The latter is .provided with a .tapered threaded recess 5 communicating with a cylindrical recess at the end thereof. On opposite sides of the reduced portion 3 are leaf springs 7, which are held by means of screw bolts" 8 or in any other suitable manner.

The cutter block consists of two portions 9 and 10, as shown inV Figure 1. These portions, when secured together, have a tapered threaded extension 11 which is held at one end by a bolt` 12. A bolty 13 at: the opposite end of the portions 9 and 10 also secures them together. The portions 9 and -10 have registering slots to forma recess 14. In this recess are disposed the cutter blades 15. As will be seen from the drawings, these cutter blades are providedl with r l laterally extending trunnions 16 which enter bores' 17 by means of-which they are journalled. Within the recess '14.- are springs 18 which are mounted on pins 19, "secured to the body portion offone of the cutter block segments, lsuch as that shown at 9.

VOne end of .each of these springsbears on the' top of the block, the other end being designed to bear on the cutter blades when the latter are in certain positions, as will be explained later.

From the foregoing description of the vai rious arts of the device, the operation thereo may be readily understood. Let us assume that a casing has been caught in the hole, so that it cannot be removed. The cause of this lies largely in the coupling or collar which secures the sections of the casing together, since this is of larger diameter than the casing. Often it is possible to tell just what joint is causing the trouble. In

such instance, the collar ripper at the bottom of the jars is lowered, together with the usual apparatus, i. e., the jars, the stem and the rope socket. In Figure 3, I have shown the position of the cutter blades 15 while the collar ripper is being lowered. It will be noted that they are ressed upon by the springs 18, so as to ho d them a ainst the sides of the casing during the movement.

ownward Thls downward movement 1s suspected collar, and then the tools are raised. When the cutter blades clear the. end of the casing section 20 (see Figure 2) they enter the recess 21 betwen the ends of the casingsections 20 and 22, which `are connected together by the collar 23, so that the cutter is thenjin the position shown in Figure 2. In order to hold the cutters in posicontinued until the cutter blades pass the I tion, or rather to prevent their swinging downwardly, I provide the pins 24, which may be made of soft metal, such as a Wire nail, and which will suffice for maintaining the cuttcrsin position until the cutting operation actually begins.

After the cutters have entered the recess 2l, the jars are operated. The ordinary 'set of jars, as is well known, consists of links, so that if the collar ripper is held stationary,\as itis in tlre present instance, by means ot the frictional contact of the leaf spring 7 on the sides of the casing, the desired movement of the upper jar will be permitted, but onA the upward movement it will cause a jerk which will drive the cutter into the end of the casing 22. At each reciprocation ot' the jars, the cutter is further advanced so that eventually it reaches the position shown in Figure 4. Thus it will be seen that there are two vertical slots cut in the end of the casing so'as to weaken the joint. Now when force is applied, the' casing will separate at this point.

lt will be understood that after the cuttersare in operative position, such as that shown in Figure ,2, the action of the jars will cause the shearing of the pins 24, thus permitting the cutters to swing outwardly into the position shown in Figure 4 to cut through the casing. When the casing ripper is withdrawn, the cutter blades will swing' downwardly to the dotted line position shown in Figure 4, thus permitting 'the veasy withdrawal of the tool. D

I claim:

. A casing ripper comprising a bodyvpor tion, spring means carried on the oppositesides of said body portion and adapted to frictionally engage the interior of,- a well casing when the casing ripper is lowered, a cutter block composed of two sections, means for securing the sections together, means for securing the united sections to the body portion of the casing ripper, a pair of oppositely extending, pivotally mounted cutter meanstor normally pressing the cutter blades outwardly, pins -for limiting the pivotall movement ot' the cutter blades while the blades are being brought to operative position, said pins being subsequently sheared by the cutter blades during the cutting operation, whereby a further pivotal movement of the blades is permitted.

2. A-casing ripper comprising a body pors t1on having a tapered threaded recess, a

cutter block composed of two sections adapted to be secured together and having contiguous portions constituting an extension and threaded to enter the threaded recess in the socket, -said sections having registering recesses constituting a slot, and registering bores, and cutter blades disposed in said slot and haying trunnions Yarranged to enter said bores.

3. A casing ripper comprising a body portion having a tapered threaded recess, a cutter block composed of twosections adapted to be secured together and having contiguous portions constituting an extension' blades carried by said cutter block, spring 

